MOFs as an electron-transfer-bridge between a dye photosensitizer and a low cost Ni₂P co-catalyst for increased photocatalytic H₂ generation

Weak interaction results in inefficient electron transfer from the photoexcited erythrosin B dye photosensitizer to H₂ generation co-catalyst Ni₂P, thereby leading to low H₂ generation. To address this issue, UiO-66 MOFs were used as a suitable medium for enhancing the electron transfer process. The strong π–π interaction between the benzene rings of erythrosin B dye and UiO-66 ensures efficient electron transfer from the photoexcited erythrosin B dye to UiO-66. In addition, UiO-66 can serve as the substrate for growing the Ni₂P co-catalyst. As a result, the erythrosin B dye/UiO-66/Ni₂P system offers efficient electron transfer from erythrosin B dye to UiO-66, and to Ni₂P, thereby resulting in an active H₂ generation when compared to the erythrosin B dye and Ni₂P system. The erythrosin B dye/UiO-66/Ni₂P system with an optimum Ni₂P amount of 0.69 wt% exhibits the highest H₂ evolution rate of 65 μmol h⁻¹. This value is nearly 5 times higher than that of the reference system without UiO-66 (13.8 μmol h⁻¹). The present results show the great potential of MOFs as a porous medium for enhancing the photocatalytic H₂ generation performance of conventional systems containing a photosensitizer and H₂ generation co-catalyst.